Corrosion-induced shear performance degradation of reinforced concrete beams

Abstract

Chloride-induced corrosion of reinforcement has been recognized as one of the most predominant causes of structural degradation. In this paper, experimental and numerical investigation was conducted to study the degraded shear performance of reinforced concrete beam. The corrosion of reinforcements, crack patterns, and structural behaviors of corroded specimens with various corrosion levels accelerated by the impressed current method were analyzed. The test results indicated that the corrosion-induced crack patterns have a close relationship with the level of reinforcement corrosion. Moreover, an obvious degradation of shear performance of corroded RC beams in terms of initial stiffness, cracking loads, ultimate bearing capacity, post-peak behavior, and energy dissipation capacity was observed, which became more pronounced as the corrosion level increased. When a severe corrosion level (ηa ≥ 12%) was encountered, the failure mode could even be changed from the shear-compression failure into a much more brittle diagonal splitting failure. In parallel, to numerically simulate the propagation of the main diagonal crack faithfully, the extended finite element method (XFEM) specified with an exponential softening traction-separation relationship was adopted. Moreover, to investigate the effect of corrosion-induced bond degradation, a user-defined element (UEL) was also developed to represent the interfacial bond response. The reasonable agreement between the numerical simulation and experimental results proved the feasibility of the proposed approach.